1. Field of the Invention
The present invention relates to a semiconductor device, and more specifically, it relates to a compact semiconductor device, a typical example of which is a BGA (ball grid array) semiconductor device.
2. Description of the Related Art
There has been an increasing need for achieving miniaturization and a lower profile in an integrated circuit package constituted by packaging semiconductor elements such as semiconductor integrated circuits. In response to this need, a BGA-type semiconductor device achieved by providing spherical terminals such as solder in a grid at the lower surface of a multiple-terminal semiconductor integrated circuit package has been proposed.
FIG. 10 shows the structure adopted in the BGA semiconductor device mentioned above. As shown in FIG. 10(a), a semiconductor element 802 is secured with an adhesive (not shown) or the like at the center of the upper surface of a substrate 801 of the semiconductor device main body. In addition, at the periphery of the substrate of the semiconductor device main body, a plurality of pad electrodes 806 are provided and are electrically connected with electrodes 807 at the semiconductor element 802 via wirings 803 which may be constituted of, for instance, Au.
As illustrated in FIG. 10(b), a specific range containing the semiconductor element is defined through sealing on the substrate of the semiconductor device main body by using resin 804. In addition, ball electrodes 805 constituted of solder or the like are formed at specific positions of the lower surface of the substrate 801 of the semiconductor device main body.
However, a recognition error may occur with regard to the position at which the semiconductor element is bonded onto the substrate of the semiconductor device in the related art and, in such a case, the semiconductor element may not be secured at a perfectly accurate position. If the semiconductor element is mounted at the wrong position, a problem of wire shorting or the like arises. In addition, since the substrate of the semiconductor device is normally used as a common substrate at which semiconductor elements of varying sizes and types are mounted, it is difficult to mount the various semiconductor elements at their semiconductor element mounting positions with a higher degree of accuracy. There is another issue to be addressed in that as the number of wires connected to the semiconductor device increases, the semiconductor elements need to be mounted at the exact mounting positions with an even higher degree of accuracy.